Efforts to Support:

Post-Landfill Action Network
Trash Academy
Friends of Fairmount
Friends of the Wissahickon
Plastic-free Philly

 The Science:

Blackburn, K., & Green, D. (2022). The potential effects of microplastics on human health: What is known and what is unknown. AMBIO - A Journal of the Human Environment, 51(3), 518–530. https://doi.org/10.1007/s13280-021-01589-9

(Summary) Microplastics are found in the air, and in the Mariana Trench and remote mountain peaks as well as glaciers, because they can be so small that they get evaporated up into the clouds to then fall back down with the rain. They’ve been found in products such as table salt, beer, and produce. Phthalates, the most common plasticizers, which are used as an additive to plastic to make it more flexible, have been found in household dust and human urine and breastmilk. Some evidence links exposure to phthalates to higher rates of asthma and allergies in children, and shorter pregnancies. BPA is a chemical used in plastic manufacturing, and has been linked with adverse birth outcomes. While we have a lack of data on human subjects, we do have data on the implications of plastics on animal health, and we can extrapolate human health consequences from that. From animal studies, we know that the plastic polyvinyl chloride (PVC) has carcinogenic effects and that the chemicals emitted from some plastic products cause immobility in water fleas. Tests of human cerebral and epithelial cells showed toxic stress and inflammation when exposed to microplastics. Some studies have linked exposure to polybrominated diphenyl ethers (PBDEs), another additive used as a flame retardant in many household products, to impaired neurological development in mice. Microplastics also interact with other pollutants such as heavy metals. Oysters have been found to have microplastics and trace metals. Another example is the agricultural use of polyethylene mulching sheets, which absorb pesticides, thus becoming a carrier into other environments as the plastic breaks down. Other chemicals that could be transported due to their high rate of absorption to microplastics include antibiotics and steroid hormones. Polychlorinated biphenyls (PCBs), used in plastic production in the 1970s, have been found in high toxicity levels in dolphins and orcas, which could lead to reproductive failure and other health issues. However, if the gut of an animal is already highly contaminated with chemicals, microplastics can absorb those chemicals and this process actually cleans the gut. For this reason, some researchers say this exposure pathway is of less concern than others. Plastic textile fibers account for 16% of the world's plastic production. They have found the smallest particles suspended in air across the globe, outdoors and especially indoors. The human health implications of inhaling plastic are not well-understood, but some studies show that it can cause inflammation and lesions. 87% of patients undergoing lung tumor removal were found to have plastic fibers in their lung tissue. One study links plastic fiber inhalation in a factory setting to cancer, although other studies dispute this but admit to increased respiratory irritation. Translocation of microplastics within the bodies of mice have been studied; microplastics traveled from the nasal passageway to the spleen within ten days. Some microplastics are small enough to cross the placental barrier in mice. Pregnant mice exposed to microplastics have been observed to produce offspring with fatty acid metabolic disorders. Again, research is lacking with human subjects. Studies regarding ingestion also hardly ever include humans, but mostly aquatic animals, although one study found microplastics in human stool samples. Due to the heat often applied to infant feeding bottles, babies can have 2600 times the adult daily consumption of microplastics. Studies of zebrafish have associated microplastic ingestion with inflammation and adverse liver reactions. Another study of fish found higher lipid peroxidation levels that suggested brain damage. Fish larvae and juveniles that were fed plastic-contaminated food showed effects could include death, developmental abnormalities, DNA breaks, and changes in swimming behavior. One case showed granulomas formed in the liver of a human patient in response to the accumulation of debris from their hip prosthetic. Lab studies have shown that fungi, bacteria, and biofilms can degrade some plastics. Pathogenic bacteria has been found on microplastics floating in the North and Baltic Sea. Some bacteria on microplastics have been found to be more resistant to antibiotics than bacteria in water. Antibiotic-resistant bacteria are able to form a biofilm on microplastics that encourages a horizontal gene transfer that would otherwise be impossible in water alone. This evidence shows that microplastics could lead to superbugs.     

Behind-the-Scenes:

(A Special Thanks to Tyler A. Davis Photography)

Teaching Youth about Plastic-Eating Bacteria:

It has been my great pleasure to teach youth about plastic-eating bacteria as a Teaching Artist with Mural Arts Philadelphia alongside Teaching Artist Patric Dempsey. I am inspired by so many artists in Philadelphia, and Patric has another environmental project of note that I wanted to share:

Kensington Color me Back Project

"Being given an opportunity through this project to implement my artistic experience toward benefiting the community has been very insightful and uplifting as a growing creative professional trying to find what places I really want to pour my energy and creative thinking into. It's been a fun challenge to design projects that are thoughtful and conducive for our site, and developing workshops that are simple, but leave room for creative expression and experimentation.